I have no idea why you wouldn't run a 5k flash vert on the street. To think you can't is an old wives tale. I have on every car i have had, with zero issues. Converters these days have come a long ways from where they were years ago.
Chances are, they are better than a typical 10 inch 3500 “street” vert, which are typically way less efficient than an 8 inch is.
Btw..does your car weigh 3180 or 3450, you have posted both in this thread. Big difference